add C strace-grate

[drapl0n]

This PR adds C strace grate. I have currently disabled handler registration for exec and clone syscalls.

Compile using:

lind_compile --compile-grate strace_grate.c strace.c

[stupendoussuperpowers]

1. Can you follow the directory structure of imfs_grate and geteuid_grate as well? i.e. place all the .c/.h files in src/, and add a compile script which will place the .wasm/.cwasm files in output/?

2. Does this convert arguments to strings as well or is that a TODO?

[drapl0n]

1. Can you follow the directory structure of imfs_grate and geteuid_grate as well? i.e. place all the .c/.h files in src/, and add a compile script which will place the .wasm/.cwasm files in output/?

Latest version of lind_compile has a flag that facilitates compilation of the grate and copies pre-compiled binary to lindfs, which i think is pretty streamlined.

Does this convert arguments to strings as well or is that a TODO?

Yes, it does convert syscall arguments with type ARG_STR into a string.

[stupendoussuperpowers]

Let me know when all the changes are in so that I can more thoroughly review the code. Housekeeping comments:

• Latest version of lind_compile has a flag that facilitates compilation of the grate and copies pre-compiled binary to lindfs, which i think is pretty streamlined.

  The compile_grate.sh script can simply be invoking lind_compile --compile-grate, but we should have that script.

  1. The only information about how to compile this in this PR description.
  2. This helps with automation, such as for the benchmark tests. Right now I would have to guess which order I should supply these .c files to lind_compile and the output binary will be named differently based on what order I pick.

  This is more or less standard practice for standalone projects to have a Makefile-esque thing.

• Add a README

• Add some basic unit-tests